Set seed in pre-watered pots or trays of free-draining compost and cover with 6mm (1/4in) compost or vermiculite. Do not water in. Place in a propagator or clear polythene bag at 18-21°C (65-70°F). Remove lids/ bags after germination, which takes 7-10 days.
Transplant tray seedlings into 7.5cm (3in) pots once large enough to handle. Grow on indoors until around 20cm (8in) tall and/or all frost risk has passed. Plant outside 45cm (18in) apart, or set 3 plants per grow bag. Support plants with canes and remove sideshoots for the best yields. Never allow soils/compost to dry out and feed regularly once the first truss has set.